From patchwork Wed May 18 23:50:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 12854383 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1FB91C352AA for ; Wed, 18 May 2022 23:53:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231609AbiERXxg (ORCPT ); Wed, 18 May 2022 19:53:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54936 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231201AbiERXxd (ORCPT ); Wed, 18 May 2022 19:53:33 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5FF109BAFC; Wed, 18 May 2022 16:53:32 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 121FDB82257; Wed, 18 May 2022 23:53:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 69F19C34118; Wed, 18 May 2022 23:53:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652918009; bh=yHkjjFgPWBAM7ugXVTMsE7MeQw6lNau0sWLXQYhemjQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U+vswUshzS2JZAeaZrQ+4R1JogbOEdkBJFDHz8XBpOHRMP+e3IIt4z5+z9wm3oL2O HvCC0qNI96X1HuADp2nF7J1rWWw0u7A5Lf0lTRyYvDuQdaNZXjLoLhjyFV62NmkCBY 1QpHXI9NecyqoTvXFSn9PT1QmDUTrAm4P1xTaSiY2hHzZdfrnCIn6otPkl0y1i/dxh 0qI6LbOQ4qt/bnKKHSiNIm+XzachEBhVyC8cRZrn3IRse920bLke7nxN7wkVPVS/eK jLQpMy/iJU4hnp1ZTh3EWFUOOVP00jgba2Db1nkOC3MEFtuC4K4P+v4x7ynGsL28T/ CHzEOkd21WvtA== From: Eric Biggers To: linux-fsdevel@vger.kernel.org Cc: linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, linux-api@vger.kernel.org, linux-fscrypt@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Keith Busch Subject: [RFC PATCH v2 2/7] fscrypt: change fscrypt_dio_supported() to prepare for STATX_IOALIGN Date: Wed, 18 May 2022 16:50:06 -0700 Message-Id: <20220518235011.153058-3-ebiggers@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220518235011.153058-1-ebiggers@kernel.org> References: <20220518235011.153058-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Eric Biggers To prepare for STATX_IOALIGN support, make two changes to fscrypt_dio_supported(). First, remove the filesystem-block-alignment check and make the filesystems handle it instead. It previously made sense to have it in fs/crypto/; however, to support STATX_IOALIGN the alignment requirement would have to be returned to filesystems. It ends up being simpler if filesystems handle this part themselves, especially for f2fs which only allows fs-block-aligned DIO in the first place. Second, make fscrypt_dio_supported() work on inodes whose encryption key hasn't been set up yet, by making it set up the key if needed. This is required for statx(), since statx() doesn't require a file descriptor. Signed-off-by: Eric Biggers --- fs/crypto/inline_crypt.c | 48 +++++++++++++++++++++------------------- fs/ext4/file.c | 9 ++++++-- fs/f2fs/f2fs.h | 2 +- include/linux/fscrypt.h | 7 ++---- 4 files changed, 35 insertions(+), 31 deletions(-) diff --git a/fs/crypto/inline_crypt.c b/fs/crypto/inline_crypt.c index 93c2ca8580923..82df4c0b9903c 100644 --- a/fs/crypto/inline_crypt.c +++ b/fs/crypto/inline_crypt.c @@ -370,43 +370,45 @@ bool fscrypt_mergeable_bio_bh(struct bio *bio, EXPORT_SYMBOL_GPL(fscrypt_mergeable_bio_bh); /** - * fscrypt_dio_supported() - check whether a DIO (direct I/O) request is - * supported as far as encryption is concerned - * @iocb: the file and position the I/O is targeting - * @iter: the I/O data segment(s) + * fscrypt_dio_supported() - check whether DIO (direct I/O) is supported on an + * inode, as far as encryption is concerned + * @inode: the inode in question * * Return: %true if there are no encryption constraints that prevent DIO from * being supported; %false if DIO is unsupported. (Note that in the * %true case, the filesystem might have other, non-encryption-related - * constraints that prevent DIO from actually being supported.) + * constraints that prevent DIO from actually being supported. Also, on + * encrypted files the filesystem is still responsible for only allowing + * DIO when requests are filesystem-block-aligned.) */ -bool fscrypt_dio_supported(struct kiocb *iocb, struct iov_iter *iter) +bool fscrypt_dio_supported(struct inode *inode) { - const struct inode *inode = file_inode(iocb->ki_filp); - const unsigned int blocksize = i_blocksize(inode); + int err; /* If the file is unencrypted, no veto from us. */ if (!fscrypt_needs_contents_encryption(inode)) return true; - /* We only support DIO with inline crypto, not fs-layer crypto. */ - if (!fscrypt_inode_uses_inline_crypto(inode)) - return false; - /* - * Since the granularity of encryption is filesystem blocks, the file - * position and total I/O length must be aligned to the filesystem block - * size -- not just to the block device's logical block size as is - * traditionally the case for DIO on many filesystems. + * We only support DIO with inline crypto, not fs-layer crypto. * - * We require that the user-provided memory buffers be filesystem block - * aligned too. It is simpler to have a single alignment value required - * for all properties of the I/O, as is normally the case for DIO. - * Also, allowing less aligned buffers would imply that data units could - * cross bvecs, which would greatly complicate the I/O stack, which - * assumes that bios can be split at any bvec boundary. + * To determine whether the inode is using inline crypto, we have to set + * up the key if it wasn't already done. This is because in the current + * design of fscrypt, the decision of whether to use inline crypto or + * not isn't made until the inode's encryption key is being set up. In + * the DIO read/write case, the key will always be set up already, since + * the file will be open. But in the case of statx(), the key might not + * be set up yet, as the file might not have been opened yet. */ - if (!IS_ALIGNED(iocb->ki_pos | iov_iter_alignment(iter), blocksize)) + err = fscrypt_require_key(inode); + if (err) { + /* + * Key unavailable or couldn't be set up. This edge case isn't + * worth worrying about; just report that DIO is unsupported. + */ + return false; + } + if (!fscrypt_inode_uses_inline_crypto(inode)) return false; return true; diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 6feb07e3e1eb5..de153b508b20a 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -40,8 +40,13 @@ static bool ext4_dio_supported(struct kiocb *iocb, struct iov_iter *iter) { struct inode *inode = file_inode(iocb->ki_filp); - if (!fscrypt_dio_supported(iocb, iter)) - return false; + if (IS_ENCRYPTED(inode)) { + if (!fscrypt_dio_supported(inode)) + return false; + if (!IS_ALIGNED(iocb->ki_pos | iov_iter_alignment(iter), + i_blocksize(inode))) + return false; + } if (fsverity_active(inode)) return false; if (ext4_should_journal_data(inode)) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 8c570de21ed5a..271509b1c7928 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -4469,7 +4469,7 @@ static inline bool f2fs_force_buffered_io(struct inode *inode, struct f2fs_sb_info *sbi = F2FS_I_SB(inode); int rw = iov_iter_rw(iter); - if (!fscrypt_dio_supported(iocb, iter)) + if (!fscrypt_dio_supported(inode)) return true; if (fsverity_active(inode)) return true; diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index 50d92d805bd8c..6ca89461d48dc 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -714,7 +714,7 @@ bool fscrypt_mergeable_bio(struct bio *bio, const struct inode *inode, bool fscrypt_mergeable_bio_bh(struct bio *bio, const struct buffer_head *next_bh); -bool fscrypt_dio_supported(struct kiocb *iocb, struct iov_iter *iter); +bool fscrypt_dio_supported(struct inode *inode); u64 fscrypt_limit_io_blocks(const struct inode *inode, u64 lblk, u64 nr_blocks); @@ -747,11 +747,8 @@ static inline bool fscrypt_mergeable_bio_bh(struct bio *bio, return true; } -static inline bool fscrypt_dio_supported(struct kiocb *iocb, - struct iov_iter *iter) +static inline bool fscrypt_dio_supported(struct inode *inode) { - const struct inode *inode = file_inode(iocb->ki_filp); - return !fscrypt_needs_contents_encryption(inode); }